Conventionally, small electronic devices and the like use transformers and chip coils that are made by winding twisted wires around a core. For example, JP 11-097274A discloses a winding method comprising causing wires to respectively pass through a plurality of nozzles provided in parallel with each other, rotating the plurality of nozzles about a rotation axis which is parallel with the nozzles so as to twist the wires, and winding the twisted wires around a core.